Engine



June 18, 1929. H, w. STUVER ENGINE Filed May 28, 1927 2 Sheets-Sheet 2 I N VEN TOR.

ATTORNEY.

Patented June 18, 1929.

UNITED STATES HENRY'W; s'ruvnn, or DENVER, COLORADO.

ENGINE.

Application filed May 28,

My invention relates to internal combustion engines, andparticularly to two-cycle engines. 7, An object of the invention is to take advantage in an internal combustion engine of the physical law that the force of a combus-, tion is equally great in opposite directions. Heretofore it has been customary to apply the force of the combustion to the head of a driving piston. .An object of the present in vention is to provide an internal combustion engine in which the combustion takes place between two movable elements.

Then it is a further object to connect these two movable elements with a single drive shaft of the engine.

Another object is to provide concentric pistons, one of which reciprocates within the other, the larger piston providing the explosion chamber.

Other objects reside in details of construction which will more fully appear in. the course of the following description. I

An embodiment of my invention has been shown in the accompanying drawings, in which like parts are similarly designated throughout the several views, and in which Figure 1 represents a sectional elevation of an internal combustion engine embodying the features of the present invention the pistons being shown in the firing position;

Figure 2, a view similar to Figure l'except thatthe firing chamber of the engine is in an exhausting position, these two figures show the pistons at the ends of their strokes;

Figure 3, a fragmentary sectional View looking in the direction of the arrow A of Figure 2; I f

Figure 4, a view similar to'Figure 3, show- .ing a modified method of attaching the pistons to the crank shaft;

ing a modified construction;

Figure 5, a-view similar to Figure 1, show- Figure 6, a view similar to Figure 2, but .showing the modified,construction'of Figure 5' 1 Figure 7, a sectional View taken on the line 7-7 of Figure-6; and I Figure 8, a sectional View taken onthe line 8-8 of Figure .7. Referring more specifically to the drawings, the reference numeralB-represents the .crank case of-the engine and 6 the wall of the enginecylinder 36. v V

A water jacket 7 surrounds the wall to provide a passage around theengine for liquid 1927. Serial No. 195,076.

with which to cool the engine. A crank shaft 8 may be j ournaled in any suitable manner.

Concentric, telescoping trunk pistons 9 and 10, the latter piston providing a cylinder for the piston 9, are fastened to the crank shaft 8 by means of connecting rods 12 and 13 respectively. The outer piston 10 may be connected by one or more connecting rods to the crank schaft, as shown in Figures 3 and 4. The smaller piston 9 has a wristpin 1 1 ournaled in standard bosses on the inside thereof. As shown in sheet one of the drawings, the outer or combination piston 10 is pivotally fastened to the connecting rod or rods 13 by means of a pin or pins 15.

The rods 13 of the outer piston and the rod The smaller piston 9 has adefiector 17 on the top thereof, the purpose of which will be hereinafter explained. The inside surface of the top of the larger piston has a similarly formed; recess to receive the deflector. forms a cylinder interiorly thereof for the smaller piston 9, thus providing a combination piston and cylinder.

A spark plug 18 is fixed inan opening in the wall 6 of the engine cylinder and is connected with a suitable source of electrical energy to produce an electrical spark when a port 20 of the larger piston registers with the opening containing the plug. A second plug 19 is disposed at the highest point of the piston cylinder and .moves therewith. This plug may be connected by an extensible coil of wire 21, or any other suitable means, to a binding post 22 mounted on the wall of the engine cylinder but insulated therefrom by porcelain 23. The post 22-is con nected with a source of electric energy to fire simultaneously with the plug 18. This construction provides multiple means for ignit- The wall of the larger piston 10 ing the compressed gas in the firing chamber.

of battle plates 26 extending from the sides thereof, is connected with the interior of the engine cylinder by means of two passages 28 and 29disposed to register with ports 20 and 35inthe wall ofthe outer pistolyand the chamber 25 has a depression or sump 30 to collect fuel that has dripped from the baflles 26. The chamber 25 is furthermore connected with the piston chamber at the upper end thereof by a passage 38.

Exhaust ports 31 and 32 in the mantle of the outer piston are disposed to register with the exhaust passages 33 and 34 in the cylinder wall respectively as the pistons complete their outward strokes. The port 32 and the passage 34 are preferably larger than the intake passage 28 and the port 35, so that the exhaust port 32 and passage 34 are partly in register before the intake ports 35 and 20 and passages 28 and 29 begin to register respectively. This allows a substantial amount of spent gases to exhaust before any new fuel is taken in.

In the modification shown in Figures 5 and 6 of the drawings, an additional spark plug or igniter 40 is shown. This plug may be and preferably is connected with a separate source of electric energy. i

A port 41 in the larger piston 10 is positioned to register with the spark plug 40 when the chamber 27 is in its firing position. The port likewise registers with an exhaust passage 42 when the chamber 27 is in the exhausting position. Thus fresh gas that is fed in through the intake passage 29 will force some of the spent gases of the previous combustion out through the passage port 41 and passage 42 when the larger cylinder is in the position shown in Figure 6.

The intake port in the modified construction is shown at 43 in Figures 5 and 6. This intake must not register with the port 41 at any time.

Another difference that will be noted in the modified construction is that pins 44 and 45 are used in connecting both pistons with the crank shaft. The pin 44 is mounted in the piston 9 as previously described, but the pin 45 is supported in bosses 46 on the outside of the outer piston, which bosses travel in grooves-47 in the body of the engine block 48.

The pins 44 and 45 have been set off center in the pistons as shown in Figures 5, 6 and 8, so that the connecting rods 12 and 13 will not strike these pins during their reciprocating movement.

Otherwise the construction shown in Figures 5 and 6 is similar to that shown in Figures 1 and 2.

Only one cylinder has been shown and described, but the invention may be applied as well to a two-, four-, or six-, cylinder engine.

The operation of the present invention is as follows: The space inside the outer piston between the head thereof and the head of the inner piston, designated by the numeral 27, constitutes the combustion or firing chamber of the engine. As shown in Figure 1, when the larger piston is at the end of its inward stroke, motive fluid enters the cylinder 36 which is the space in the engine cylinder 6 between the head of the larger piston and the end wall 37 of the engine, and thence passes through the'pase sage 38 into the chamber 25.

As the large piston travels outwardly, the fuel passage 24 (or 43 in the modified construction) is closed and the fuel is compressed in the chambers 25 and 36. When the ports 35 and 20 register with the passages 28 and 29 respectively, as shown in'Figures 2 and 6, the compressed fuel is forced into the firing chamber 27. In the operation of the engine the bafile plates 26 become heated, especially the baffle plates on the water jacket wall, and super-heat as Wellas break up the fuel before it enters the combustion chamber. 7 r

When theengine is not in operation, fuel that has collected on the baffle plates 26 will condense and dripdown into the sump 30. Then upon starting the engine, the collected fuel in this sump enters the firing chamber 27 first and aids the engine in starting. The fuel entering the firing chamber 27 through the ports 20 and 35 displaces part of the spent gases from the preceding combustion, forcing said gases out through the exhaust ports 31 and 32 (or 41 and 32 inthe modified construction). The fuel entering the firing chamber 27 through the port 35 strikes the deflector 17 on the top of the smaller piston 9 and is directedupwardly thereby displacing the remaining spent gases in the firing chamber, the latter passing out through the exhaust ports and passages' Then' the pistons 9 and 10 moving together, close the ports, diminish the size of the firing chamber and compressthefuel. At or near the point of greatest compression, the port '20 registers with the stationary spark plug 18 and the port 41, in the modified construction, registers vith the plug 40), and in the operation of the engine electric sparks are produced at the various plugs at this time, igniting the compressed fuel,

which thrusts the pistons apart. This movement of the pistons is transmitted to the crankshaft by means of the rods 12nd 13 connecting the crank shaft with the pistons. When the pistons reach the position illustrated in Figures 2 or 6, the exhaust ports 31 and 32 (or 41 and 32 in the modified construction) in the mantle of the cylinder 10 register with the exhaust passages 24 and 34 (or 42 and 34 in the modified construction) respectively, and the spent gas is forced out of the cylinder 27 through these passages, as heretofore explained.

It is to be understood that although the invention is particularly adapted to engines of the internal combustion type, it may also i tion in engines in which the motive force is supplied by an expansive fluid such as steam or compressed air. Other changes in the construction or arrangement of the parts of the engine may be resorted to within the spirit of the invention as defined inthe hereunto appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. An internal combustion engine comprising a cylinder, two hollow pistons within the cylinder Working one within the other and providing a combustion space between them, ignition means for the combustion space, a crank shaft, wrist pins spanning both of the pistons interiorly, and rods connecting the wrist shaft.

2. An internal combustion engine comprising a cylinder, two hollow pistons within the cylinder working one within the other, and providing a combustion space between them, ignition means for the combustion space, a

' crank shaft, off-set wrist pins spanningthe pistons interiorly, and rods connecting the pins with opposite throws of the crank wrist pins with opposite throws of the crank shaft.

3. An internal combustion engine comprising a grooved cylinder, two pistons working one within the other and providing a combustion space between them, ignition means for the combustion space, a crank shaft, the pistons having bosses, the bosses of the outer piston being'on the outside thereof and adapted to fit in the grooves in the cylinder, wrist pins s anning the spaces between the bosses of bot pistons and rods connecting the wrist pins with opposite throws of thevcrank shaft.

' 4. In an internal combustion engine comprising a cylinder, two hollow pistons within the cylinder, working one within the other and providing a combustion space between them, ignition means for the combustion space, a crank shaft, wrist pins spanning the pistons interiorly, and rods connecting the wrist pins with opposite throws of the crank shaft, the rods being offset from the axis of the pistons.

In testimony whereof I have aflixed my signature.

HENRY W. STU VER. 

